Background: Frailty arises from the "physiologic triad" of sarcopenia, immune and neuroendocrine dysregulation. With aging, serum levels of thyroid hormones show marked changes. Objectives: To study the circulating thyroid hormones (TSH, FT3, and FT4) and determine the relationship between circulating thyroid hormones and frailty in the Elderly. Methods: This cross-sectional observational descriptive study included 50 subjects who were attending the outpatient geriatric clinic and geriatric unit at Alexandria Main University Hospital and were divided into; group A: 30 frail subjects aged ≥65 years (case group) and group B: 20 healthy subjects aged <65 years (control group) during the period from March till October 2019. Frailty assessment was done using Frail Questionnaire as well as thyroid function tests (TSH, FT3, and FT4) and other routine laboratory investigations. Anthropometric measurements were taken, including weight, height, and BMI (body mass index). Results:  No statistically significant variation between the studied candidates as regards gender (p=0.729), BMI (p=0.144), or TSH levels (p=0.401) but T3 and T4 were significantly lower in group A. with noting of weak non-significance positive results parallel between age and TSH levels (r=0.150, p=0.298), high significant moderate negative correspondence in-between age and serum FT3 levels (r=-0.530, p < 0.001) and non-significant weak negative correlation between age and FT4(r=-0.246, p=0.085).  TSH levels in group A were: (3.3%) low, (66.7%) normal, (30%) high. Level of FT3 was: (46.7%) low, and (53.3%) normal while FT4 level was: (26.7%) low, (66.7%) normal and (6.7%) high. Conclusion: Aging and frailty are associated with changes in thyroid functions in the form of significantly decreased hormonal levels including FT3 and FT4, with a non-significant change in TSH levels.